Linked Life Data

8429039

Source:http://linkedlifedata.com/resource/pubmed/id/8429039

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1993-3-9
pubmed:abstractText
We have previously observed enhanced binding of HDL and apolipoproteins A-I and A-II to human endothelial cells exposed to activated complement. Induction of these binding sites required complement activation through C9, suggesting a specific role for the C9 component of the C5b-9 complex. We now report that specific and saturable binding sites for apoA-I and -A-II are expressed by C9 polymers (polyC9), whereas little binding was observed to native monomeric C9. These data suggested an interaction of the apoproteins with a site(s) which is exposed only upon C9 polymerization, and also suggested that binding of the apoproteins to this new site might interfere with assembly of C9 into the polyC9 tubule and insertion into the cell membrane. ApoA-I was found to inhibit zinc-catalyzed polymerization of C9 in a concentration-dependent fashion. Formation of SDS-resistant C9 polymers was completely inhibited at apoA-I or -A-II concentrations > or = 5 microM. ApoA-I also produced a concentration-dependent inhibition of C9 incorporation into C5b-9 complexes on endothelial cells, which was accompanied by a corresponding decrease in SDS-resistant C9 polymers associated with the cell membrane. In summary, the ability of the HDL apoproteins A-I and A-II to interact with an activation-dependent conformer(s) of the C9 component of the C5b-9 complex appears to explain the expression of HDL binding sites on endothelial cells exposed to complement. These apoproteins are also inhibitors of C9 polymerization, which may underlie the protective effect of HDL for blood cells exposed to activated complement.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
268
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3632-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:8429039-Amino Acid Sequence, pubmed-meshheading:8429039-Apolipoprotein A-I, pubmed-meshheading:8429039-Apolipoprotein A-II, pubmed-meshheading:8429039-Binding, Competitive, pubmed-meshheading:8429039-Binding Sites, pubmed-meshheading:8429039-Cells, Cultured, pubmed-meshheading:8429039-Chromatography, Gel, pubmed-meshheading:8429039-Chromatography, High Pressure Liquid, pubmed-meshheading:8429039-Complement C8, pubmed-meshheading:8429039-Complement C9, pubmed-meshheading:8429039-Complement Membrane Attack Complex, pubmed-meshheading:8429039-Electrophoresis, Agar Gel, pubmed-meshheading:8429039-Endothelium, Vascular, pubmed-meshheading:8429039-Humans, pubmed-meshheading:8429039-Macromolecular Substances, pubmed-meshheading:8429039-Molecular Sequence Data, pubmed-meshheading:8429039-Umbilical Veins
pubmed:year
1993
pubmed:articleTitle
Interaction between apolipoproteins A-I and A-II and the membrane attack complex of complement. Affinity of the apoproteins for polymeric C9.
pubmed:affiliation
Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.